1. Field
The following description relates to a substrate level bonding method and a substrate level package, and more particularly, to a substrate level bonding method and a substrate level package that are applied to a flip chip package or an RF chip package for a general memory semiconductor chip, and a flip chip on glass package for an LCD driver chip to be used in a wafer level module.
2. Description of the Related Art
Substrate level packaging is a process in which at least two substrates are bonded in the form of a wafer such that the substrates are electrically connected to each other, and then the wafer is cut into units of chips, thereby allowing single packages to be manufactured.
Recently, in this technique, DFR (Dry Film Resist) has been used as an adhesive to bond the substrates to each other.
Since the DFR is laminated on an upper surface of the substrate in the form of a film which is not in a liquid state, the DFR can be applied to a substrate having a via hole. In addition, since the DFR is effectively welded to the substrate at a low temperature, for example, at 120° C. or below, a circuit pattern formed on the substrate is prevented from being deformed due to high temperature.
The process of bonding substrates using DFR as an adhesive includes laminating DFR on a lower substrate, curing the DFR through an exposure and then thermally bonding the outer surface of the cured DFR to a surface of an upper substrate which faces the lower substrate.
However, after the DFR has been cured, it is difficult for the DFR to adhere to the substrate while being able to adjust to the shape of a surface of the substrate to which it is to adhere. As a result, the bonding force of the DFR is degraded.